From 9816be53e531d26509d41645c2b829e511491cd6 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 26 May 2015 12:51:56 +1000 Subject: [PATCH] generic/275: writes may not partially succeed When a large IO is done as a single buffer, there is no guarantee that it will partially succeed when close to ENOSPC. The test assumes that the kernel is going to break the write down into smaller chunks (i.e. buffered IO breaking it down into PAGE_SIZE allocations), but certain configurations will not do this. e.g. extent size hints are set or DAX is being used) and hence the large write fails completely as there is not space for the entire allocation to be made. Hence break the final write in the test up into multiple small writes, thereby acheiving the same effect - ensuring that we can write more data after removing some space.... Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- tests/generic/275 | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/tests/generic/275 b/tests/generic/275 index 7382edb6..f1963d88 100755 --- a/tests/generic/275 +++ b/tests/generic/275 @@ -57,6 +57,8 @@ umount $SCRATCH_DEV 2>/dev/null _scratch_mkfs_sized $((2 * 1024 * 1024 * 1024)) >>$seqres.full 2>&1 _scratch_mount +# this file will get removed to create 256k of free space after ENOSPC +# conditions are created. dd if=/dev/zero of=$SCRATCH_MNT/tmp1 bs=256K count=1 >>$seqres.full 2>&1 [ $? -ne 0 ] && _fail "Error creating file" @@ -79,14 +81,16 @@ $DF_PROG $SCRATCH_MNT >>$seqres.full 2>&1 _freespace=`$DF_PROG -k $SCRATCH_MNT | tail -n 1 | awk '{print $5}'` [ $_freespace -gt 1024 ] && _fail "could not sufficiently fill filesystem" -# Try a write larger than available space -dd if=/dev/zero of=$SCRATCH_MNT/tmp1 bs=1M count=1 >>$seqres.full 2>&1 +# Try to write more than available space in chunks that will allow at least one +# full write to succeed. +dd if=/dev/zero of=$SCRATCH_MNT/tmp1 bs=128k count=8 >>$seqres.full 2>&1 echo "Bytes written until ENOSPC:" >>$seqres.full du $SCRATCH_MNT/tmp1 >>$seqres.full # And at least some of it should succeed. _filesize=`ls -l $SCRATCH_MNT/tmp1 | awk '{print $5}'` -[ $_filesize -eq 0 ] && _fail "write file err: Partial write until enospc failed; wrote 0 bytes." +[ $_filesize -lt $((128 * 1024)) ] && \ + _fail "Partial write until enospc failed; wrote $_filesize bytes." echo "done" status=0 -- 2.39.5